5 (More) Relational Database Management System for Linux: We have already featured here some of the best relational database management system (RDBMS) for Linux. However, there are other excellent RDBMS that we have not yet mentioned. So today, we are giving you another round of some of the best relational database management system for Linux.

Firebird is an open source relational database management system that offers superb concurrency, high performance, and powerful language support for stored procedures and triggers. It provides many ANSI SQL-99 features and has a complete set of command line utilities that enable users to make databases, recover database statistics, execute SQL commands and scripts, run backups and restores, and more. Firebird 2.5 is the most recent stable version, which features enhanced multithreading, regular expression syntax, and the ability to query remote databases. Version 3.0 is already under development and is anticipated to support stored procedures in languages such as Java and C++, and SQL window functions that restrict query results.

Here are some of the other basic features of Firebird:

* Full ACID compliant transactions

* Referential integrity

* Multi Generational Architecture

* Third party tools, including GUI administrative tools and replication tools

H2 (Hypersonic 2) is a relational database management system based on Java and supports a subset of the SQL standard. Although it also supports using the PostgreSQL ODBC driver by acting like a PostgreSQL server, its main programming APIs are SQL and JDBC. H2 can run in the client-server mode or can be embedded in Java applications. It runs fast and has a very small footprint having only around 1 MB jar file size. With H2, users can create both in-memory tables, as well as disk-based tables. Its security features include role-based access rights and encryption of the password using SHA-256 and data using the AES or the Tiny Encryption Algorithm, XTEA. It provides protection against SQL injection by enforcing the use of parameterized statements. H2 offers embedded web server with a browser-based console application. It also has command line tools to start and stop a server and for backing up and restoring databases.

Forked from MySQL 6.0, Drizzle uses SQL as its primary command language and has client/server architecture. Developers call it a smaller, slimmer and faster version of MySQL. Drizzle is aimed at the web-infrastructure and cloud computing markets. Some of its main features such as the query cache and authentication system are now plugins to the database, which follow the general theme of pluggable storage engines that were launched in MySQL 5.1. It currently supports logging to files, syslog, and remote services such as RabbitMQ and Gearman via its plugin system. Drizzle is written in C++, and stores its string data in UTF-8 format. All operating systems that conform to POSIX and have a working implementation of the GNU Autotools are supported.

Virtuoso Universal Server (also known as OpenLink Virtuoso) is a middleware and database engine hybrid that is designed to take advantage of operating system threading support and multiple CPUs. It integrates the effectiveness of a traditional RDBMS, ORDBMS, RDF, XML, virtual database, free-text, web application server and file server functionality in a single system. Instead of having dedicated servers for each of the previously mentioned functionality areas, it allows a single multithreaded server process that applies various protocols. Virtuoso offers transparent real-time access to various data sources (ODBC, JDBC, XML, and Web Services), and transparent integration of different application logic (e.g. Mono ECMA-CLI and J2EE integration). Its extensive protocol support enables it to provide Web, File, and SQL database server functionality alongside native XML storage, and Web services platform features as part of a cohesive single. For exploiting recent technology advances in realms such as Web Services, RDF Data Management, XML Data Management, Object-Relational Data Management, and Unified Storage, it offers a cross-platform workbench.

LucidDB is considered as the first and only open source relational database management system designed from the ground up to power data warehouses, OLAP servers and business intelligence systems. Because of its purpose-built architecture, it usually performs faster than standard row store databases, without any additional tuning. LucidDB is based on architectural foundations like column-store, bitmap indexing, hash aggregation, and page-level multi-versioning. It supports many advanced features from SQL:2003, which include SQL/MED and user-defined transformations written in Java. All components of LucidDB were designed with the requirements of flexible, high-performance data integration and complex query processing in mind. Additionally, completeness within the center scope of its architecture means simplicity for the user: no DBA needed.